<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
      let arr =  [1,2,2,3,3,3,4,4,5,5,5,5,6,6,7]
        //   let result = []
        //   for (const item of arr) {
        //       if(!result.includes(item)){
        //           result.push(item)
        //       }
        //   }
        //   console.log(result)

        console.log([...new Set(arr)])
        console.log(Array.from(new Set(arr)))
      
    </script>
</body>
</html>